In construction of a solar photovoltaic system, some variance may occur between the designed (planned) construction and the actual construction. Therefore, after the construction, the wiring and placement of solar photovoltaic panels are examined to obtain wiring path information and placement information. However, the examination task is not easy.
Non Patent Literature 1 discloses a technique of facilitating the above examination task. The technique investigates the wiring paths and placement by applying high frequency signals to the wiring paths and examining the paths where the signals are detected.